Trim strips are frequently used as protective and decorative accessories for motor vehicles, boats, aircraft, appliances, machines and other structures. For example, trim strips can be employed as body side molding on automobiles to provide impact protection from door strikes and also to enhance the aesthetic appeal of the automobile. Trim strips are generally formed by extruding thermoplastic material into elongated moldings which are then transversely cut to desired lengths. Considerable effort is often used to enhance the appearance of trim strips by, for example, providing an attractive end finishing or laminating a metallized film thereon.
In the past, trim strips for attachment to a vehicle have encountered various problems due to the design and manufacture of the trim strips. For instance, trim strips which are formed by extruding a thermoplastic material over a solid metal core to form an outer layer of skin about the metal core have imperfections in the outer skin. Such imperfections typically include ridges or "chatter lines" which appear in the outer skin due to vibrations which occur in the metal core during the through extrusion process.
A further problem with traditional trim strips is that the end caps of the trim have to be molded to the ends of the trim, usually using a material different than the material utilized for the outer skin of the trim strip. This results in a joint line formed between the end cap and the outer skin of the trim strip as well as color mismatch between the end caps and the outer skin.
A further problem is that molded end caps are difficult to bond securely to the end portion of the trim strip with the required joint bond strength. This has resulted in a poor end cap joint strength which in turn has resulted in a large scrap rate of such trim strips. There thus remains a need for an improved trim strip and method of making such trim strips.